Vibration control design considering quantization error for an on-off control system including input time-delay

A method by which to suppress large displacement vibration in a pneumatic isolation table is considered. An external force can be applied to the pneumatic isolation table by increasing or decreasing the air pressure in the air springs used in this system. In order to suppress large displacement vibration, it is necessary to switch the control input instantly. Therefore, the plant includes an on-off action and an input time-delay as the control input. The stabilization of this type of system is difficult using conventional linear feedback controls such as the optimal regulator. Thus, a method is proposed that ensures the system stability by changing the input based on the evaluation of quantization error arising from the on-off drive. Furthermore, the proposed method is applied to a pneumatic isolation table and its performance is verified through numerical simulations and experiments.